GT3 Cam timing headaches x 2

[c2dweller]

Please help if you can! We have 2 headaches with a GT3 engine we are re-timing the cams on.

Background:
We have a 996 GT3 MK2 with an M96.79 engine which has a high camshaft deviation on bank 2 (About 14deg). Car ran fine, albeit with a slightly lumpy tickover. We decided to see if this could be adjusted back into specification. Things I need to mention:
We are using the factory staking tools – not the Stormski style dial set up.
We are following WM150323

Our procedure:
We set-up bank 1, using overlapping TDC on cylinder 4 and fitting the staking tool.
First headache … how to set the variocam adjusting unit - is the right stop? the WM says so – so we turn it clockwise. This is different to what is prescribed for a 996 Turbo, which talks the left stop. It feels wrong to turn it to the right stop?
Turn the engine over 720deg
Recheck – all is fine.

Set-up bank 2, as described … Turn engine over 360deg.
We use overlapping TDC from cylinder 1 this time.
Second headache … staking tool fits in for the inlet, but it won’t fit in the exhaust cam. The eccentric nature means that it is way off and wouldn’t fit unless the cam was turned 180 degrees. The cam lobes are pointing outwards as described in the WM.
If we turn it another 360deg (to the crank position for bank 1 timing) the staking tool will fit.
We can’t believe the exhaust cam is 180 degrees out, as the car ran well before and the lobes are pointing in the correct direction – we just can’t fit the staking tool into the exhaust cam.
We then need to set the adjusting unit, so bump into headache 1 … which way to turn the adjusting unit? Anti-clockwise or clockwise?

So our 2 headaches are:
Which way to turn the adjusting unit?
Why doesn’t the staking tool fit in the exhaust cam on bank 2

I’d really appreciate some help on this.

Thanks in advance, Lee

[h.wong]

Hello,

Do yourself a favor and talk to Glenn Yee at GYM in San Dimas, CA.

Good luck,
Harry

[c2dweller]

Thanks for the recommendation. I have sent Glenn an email - I hope he reads it.

Things have developed:
> We realised the timing staking tools were incorrect - they were for a Mk1 GT3, not a Mk2.

The problem we have now - when the camshaft adjuster is turned against the left stop (anticlockwise) and the staking tool is removed, it jumps back (the cam lobe is compressing the valve which then pushes the cam back when there is nothing to hold it in place). I don’t think it’s a variocam fault as both sides behave the same way.

The chain tensioner tool is used and we are using the inlet adjuster wrench.

We have not performed this procedure before and wanted to check this is normal. The instruction suggests that after 720 degrees crank (360 degrees cam) rotation, the staking tool should fit back in, but it doesn’t ... because it jumped back the moment the staking tool was removed.

Thanks in advance.

[bobt993]

This similar to the 996 TT setup. Same mistake was made while timing my motor after a the heads were rebuilt. You can use the keyway method and must turn back against the engine direction then lock down the timing gear. If not you will be about 14 to 16 degs out. Both sides must be turned back against the chain direction. The Stomski tools work just fine.

[h.wong]

Lee,

Talked with Glenn Yee.. he has not received your email..

just call him... He said he will be around next week..

GYM 1 909 592-1570 good luck!

Harry

[tharbert]

Eeek, water pumpers!